Recommendations For Replacement Pump Or Pump Motor (1.5" Piping, High Head)

[mas985]

A reduction in the impeller size reduces both the flow rate and motor's energy consumption. The impeller is the load for the motor. A smaller impeller is a smaller load so the motor does not need as much energy to spin the impeller and energy consumption drops. The energy factor as measured by gallons pumped per watt-hr consumed is higher with a smaller impeller so the energy efficiency is better. So yes, a smaller impeller is worth it especially since it costs much much less than a new pump. Usually the impeller and seal can be had for less than $50.

http://www.amazon.com/Hayward-Series.../dp/B0037V0S3S

I hate to sound like a broken record but your current flow rate is irrelevant. If you are interested in reducing energy consumption all you need is a smaller impeller and/or pump. A two speed motor just adds another level of energy efficiency.

BTW, I kind of lost track of what your primary objective. I know you are having issues with the system but can you recap what your objective is with this whole thing?